If your NST is not running software 1.2.1 update the software. The software updates improved Wifi.
Is there a reason why you are using WEP? WEP is not secure anymore. If you can, try WPA2.
Some router things to check:
- Do not use spaces or other special characters in your SSID.
- Use only lower case letters for the SSID, no upper case.
- In case of an N speed router set speed to G, not G/N mixed.
- Check if router is running the latest firmware, otherwise update.